Ultrasonic bonders are known in the art. Stationary plunge-horn ultrasonic bonders are limited to operating on webs traveling at low speeds because, among other reasons, at higher web speeds, the web being operated on tends to pile up, or bunch up, at the leading edge of the plunge-type stationary ultrasonic horn.
Some known ultrasonic bonders provide end seals for articles by using plunge type ultrasonic horns. The plunge type ultrasonic horns lift up from the anvil a distance sufficient to enable an article, generally containing a product, to pass thereby.
Many ultrasonic bonders maintain the ultrasonic horn in engaging contact with the anvil continuously, whether or not bonding occurs. Such an arrangement decreases the probability of damage to the horn or anvil due to bounce or chatter from the force of the horn and anvil recontacting one another after being separated from each other. The web speed for such a system generally is less than about 150 meters/minute. Typical production speeds for ultrasonic bonders are on the order of 10-30 meters/minute.